flush_tlb_all_local:

Hi all,

into parisc/kernel/pacache.S, i find this:
[...]
flush_tlb_all_local:
[...]

        rsm     PSW_SM_Q,%r0       /* Turn off Q bit to load iia queue */
        ldil    L%REAL_MODE_PSW, %r1
        ldo     R%REAL_MODE_PSW(%r1), %r1
        mtctl   %r1, %cr22
        mtctl   %r0, %cr17
        mtctl   %r0, %cr17

[...]

Why twice 'mtctl %r0, %cr17'?

and also:
[...]
fitmanymiddle: /* Loop if LOOP >= 2 */
ADDIB> -1,%r31,fitmanymiddle /* Adjusted inner loop
decr */
pitlbe 0(%sr1,%r28)
pitlbe,m %arg1(%sr1,%r28) /* Last pitlbe and addr
adjust */

Typicaly the function name is flush_..., so why do we 'purge' here?

Thanks in advance for help,
Joel

Good question. No clue. Looks like a brain fart since clearing it
once should work unless there's a weird bug. I'll remove it.

AFAICT, because purge is sufficient.
It doesn't look like parisc even provides a FITBLE instruction.

thanks,
grant

definitely not a brainfart. Read PA2.0 arch book (section 2) where it talks about cr17/cr18. CR17 is two registers and writing it twice clear both head/tail of the IIAS. Just like cr18 is also written twice.

sorry for not catching that the first time around. grant

Probably, there should be a comment in the code noting this special behavior.

Dave

J. David Anglin                                  [email protected]
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

Done. They're deliberately a little bit cryptic to ensure that people actually go and look at the arch book, but they are different so people don't think this might be a merge error.

"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk